GRB 250330B
GCN Circular 39951
Subject
GRB 250330B: Fermi GBM Final Real-time Localization
Date
2025-03-30T22:03:10Z (2 months ago)
From
Fermi GBM Team at MSFC/Fermi-GBM <do_not_reply@GIOC.nsstc.nasa.gov>
Via
email
The Fermi GBM team reports the detection of a likely SHORT GRB
At 21:52:22 UT on 30 Mar 2025, the Fermi Gamma-ray Burst Monitor (GBM) triggered and located GRB 250330B (trigger 765064347.102666 / 250330911).
The on-ground calculated location, using the Fermi GBM trigger data, is RA = 114.1, Dec = 13.3 (J2000 degrees, equivalent to J2000 07h 36m, 13d 18'), with a statistical uncertainty of 3.1 degrees.
The angle from the Fermi LAT boresight is 81.0 degrees.
The skymap can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250330911/quicklook/glg_skymap_all_bn250330911.png
The HEALPix FITS file, including the estimated localization systematic, can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250330911/quicklook/glg_healpix_all_bn250330911.fit
The GBM light curve can be found here:
https://heasarc.gsfc.nasa.gov/FTP/fermi/data/gbm/triggers/2025/bn250330911/quicklook/glg_lc_medres34_bn250330911.gif
GCN Circular 39952
Subject
Fermi GRB 250330B: Global MASTER-Net observations report
Date
2025-03-30T23:15:59Z (2 months ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <lipunov@xray.sai.msu.ru>
Via
email
V.Lipunov, E.Gorbovskoy, N.Tiurina, P.Balanutsa, , D.Vlasenko, I.Panchenko,
A.Kuznetsov, G.Antipov, A.Sankovich, A.Sosnovskij, Yu.Tselik, M.Gulyaev, Ya.Kechin,
V.Senik, A.Chasovnikov, K.Labsina, I. Gorbunov (Lomonosov MSU),
O.Gress, N.Budnev (ISU),
C.Francile, F. Podesta, R.Podesta, E. Gonzalez (Observatorio Astronomico Felix Aguilar (OAFA),
A. Tlatov, D. Dormidontov (Kislovodsk Solar Station of the Pulkovo Observatory),
A. Gabovich, V.Yurkov (Blagoveschensk Educational StateUniversity)
D.Buckley (SAAO),
R.Rebolo (The Instituto de Astrofisica de Canarias),
L.Carrasco, J.R.Valdes, V.Chavushyan, V.M.Patino Alvarez, J.Martinez,
A.R.Corella, L.H.Rodriguez (INAOE, Guillermo Haro Astrophysics Observatory)
MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) started inspect of the Fermi GRB 250330B ( Fermi GBM team, GCN 39951) errorbox 54 sec after notice time and 92 sec after trigger time at 2025-03-30 21:53:54 UT, with upper limit up to 17.4 mag. The observations began at zenith distance = 77 deg. The sun altitude is -59.7 deg.
The galactic latitude b = 16 deg., longitude l = 206 deg.
Real time updated cover map and OT discovered available here:
https://master.sai.msu.ru/site/master2/observ.php?id=2828695
We obtain a following upper limits.
Tmid-T0 | Date Time | Site | Coord (J2000) |Filt.| Expt. | Limit| Comment
_________|_____________________|_____________________|____________________________________|_____|_______|_______|________
102 | 2025-03-30 21:53:54 | MASTER-SAAO | (07h 22m 19.10s , +12d 01m 03.3s) | C | 20 | 17.1 |
141 | 2025-03-30 21:54:33 | MASTER-SAAO | (07h 22m 19.82s , +12d 01m 05.9s) | C | 20 | 17.0 |
186 | 2025-03-30 21:55:12 | MASTER-SAAO | (07h 22m 20.65s , +12d 01m 08.5s) | C | 30 | 17.1 |
240 | 2025-03-30 21:56:01 | MASTER-SAAO | (07h 22m 21.73s , +12d 01m 11.2s) | C | 40 | 17.0 |
304 | 2025-03-30 21:57:00 | MASTER-SAAO | (07h 22m 23.03s , +12d 01m 14.3s) | C | 50 | 16.9 |
378 | 2025-03-30 21:58:10 | MASTER-SAAO | (07h 22m 24.54s , +12d 01m 18.1s) | C | 60 | 16.9 |
629 | 2025-03-30 22:02:21 | MASTER-SAAO | (07h 36m 00.30s , +13d 19m 14.0s) | C | 60 | 17.4 |
709 | 2025-03-30 22:03:40 | MASTER-SAAO | (07h 36m 01.77s , +13d 19m 17.5s) | C | 60 | 17.4 |
788 | 2025-03-30 22:04:59 | MASTER-SAAO | (07h 36m 03.30s , +13d 19m 20.6s) | C | 60 | 17.4 |
Filter C is a clear (unfiltred) band.
The observation and reduction will continue.
The message may be cited.
GCN Circular 39989
Subject
GRB 250330B: EIRSAT-1 GMOD Detection
Date
2025-03-31T23:14:24Z (2 months ago)
From
David Murphy at University College Dublin <david.murphy@ucd.ie>
Via
Web form
D. Murphy, J. Fisher, C. de Barra, P. McDermott, C. McKenna, A. Ulyanov, G. Finneran, G. Corcoran, L. Cotter, A. Empey, F. Gibson Kiely, J. Thompson, D. McKeown, A. Martin-Carrillo, L. Hanlon, S. McBreen, on behalf of the EIRSAT-1 team:
EIRSAT-1 reports the detection of the short gamma-ray burst GRB 250330B by the Gamma-ray Module (GMOD) instrument, which was also detected by Fermi GBM (GCN [39951](https://gcn.nasa.gov/circulars/39951)). The GMOD detection was made starting at 2025-03-30 21:52:22.4 UTC.
The GMOD light curve for GRB250330B, with 1.2s binning, shows a single peak, consistent with the detection by Fermi GBM.
The spacecraft location at time of detection was 1.704 S, 7.769 E and an altitude of 407.7 km.
The light curve for this event as measured by GMOD can be found here: https://grb.eirsat1.ie/250330B/250330B_LC_onboard_preliminary.png
EIRSAT-1 is Ireland’s first satellite ([Doyle et al. Proceedings of the 4th SSEA, 2022](https://researchrepository.ucd.ie/bitstreams/2f3fdccb-6e36-4ac1-88cd-4e80feecf446/download)). It is a 2U CubeSat and carries onboard a number of experiments including the Gamma-Ray Module (GMOD), a novel, compact, gamma-ray detector ([Murphy et al, Experimental Astronomy, 53, 961–990, 2022](https://link.springer.com/article/10.1007/s10686-022-09842-z)). GMOD consists of a 25 mm × 25 mm × 40 mm Cerium Bromide scintillator coupled to SiPMs and is designed to detect gamma-ray bursts in the ~ 60 keV - 1.5 MeV range. EIRSAT-1 was developed in University College Dublin with support from ESA’s Fly Your Satellite! programme and was launched on 1st December 2023.
GCN Circular 39993
Subject
GRB 250330B: SVOM/GRM observation of a short burst
Date
2025-04-01T04:33:43Z (2 months ago)
From
Yue Wang <m18509381757@163.com>
Via
Web form
SVOM/GRM team: Yue Wang, Chen-Wei Wang, Jia-Cong Liu, Shi-Jie Zheng, Yue Huang, Shao-Lin Xiong, Shuang-Nan Zhang (IHEP)
SVOM/ECLAIRs team: O. Godet, Jean-Luc Atteia (IRAP), Frédéric Piron (LUPM), Stéphane Schanne (CEA)
Report on behalf of the SVOM team:
SVOM/GRM was triggered in-flight by GRB 250330B (SVOM trigger reference: sb25033007) at 2025-03-30T21:52:22.100 (T0). This burst was also detected by Fermi/GBM (Fermi GBM Team, GCN 39951).
With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of single main pulse with a T90 of 0.48 +0.32/-0.11 s in the 15-5000 keV band.
In addition, ECLAlRs was taking data and did not trigger, since the position of this burst, as determined by Fermi/GBM (GCN 39951, RA: 114.1 deg, DEC: 13.3 deg, Error: 3.1 deg), is located at about 96.2 degrees from the SVOM optical axis, and outside the ECLAIRs field of view.
The SVOM/GRM light curve can be found here:
https://www.bursthub.cn//admin/static/svgrb250330B.png
The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), National Center for Space Studies (CNES, France) and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS.
The SVOM/GRM point of contact for this burst is: Yue Wang (IHEP) (yuewang@ihep.ac.cn)
GCN Circular 40235
Subject
GRB 250330B: GRBAlpha detection
Date
2025-04-24T14:56:21Z (a month ago)
From
Jakub Ripa <ripa.jakub@gmail.com>
Via
Web form
J. Ripa, M. Dafcikova (Masaryk U.), A. Pal (Konkoly Observatory), N. Werner (Masaryk U.), M. Ohno, H. Takahashi (Hiroshima U.), L. Meszaros, B. Csak (Konkoly Observatory), N. Husarikova, F. Munz, M. Topinka, M. Duriskova, M. Kolar, L. Szakszonova, J.-P. Breuer, F. Hroch (Masaryk U.), T. Urbanec, M. Kasal, A. Povalac (Brno U. of Technology), J. Hudec, J. Kapus, M. Frajt (Spacemanic s.r.o), R. Laszlo, M. Koleda (Needronix s.r.o), M. Smelko, P. Hanak, P. Lipovsky (Technical U. of Kosice), G. Galgoczi (Wigner Research Center/Eotvos U.), Y. Uchida, H. Poon, H. Matake (Hiroshima U.), N. Uchida (ISAS/JAXA), T. Bozoki (Eotvos U.), G. Dalya (Eotvos U.), T. Enoto (Kyoto U.), Zs. Frei (Eotvos U.), G. Friss (Eotvos U.), Y. Fukazawa, K. Hirose (Hiroshima U.), S. Hisadomi (Nagoya U.), Y. Ichinohe (Rikkyo U.), K. Kapas (Eotvos U.), L. L. Kiss (Konkoly Observatory), T. Mizuno (Hiroshima U.), K. Nakazawa (Nagoya U.), H. Odaka (Univ of Tokyo), J. Takatsy (Eotvos U.), K. Torigoe (Hiroshima U.), N. Kogiso, M. Yoneyama (Osaka Metropolitan U.), M. Moritaki (U. Tokyo), T. Kano (U. Michigan) -- the GRBAlpha collaboration.
The short-duration GRB 250330B (Fermi/GBM detection: GCN 39951; EIRSAT-1/GMOD detection: GCN 39989; SVOM/GRM detection: GCN 39993; Wind/Konus detection trigger at 2025-03-30 21:52:22.793 UTC) was observed by the GRBAlpha 1U CubeSat (Pal et al. 2023, A&A, 677, 40; https://ui.adsabs.harvard.edu/abs/2023A%26A...677A..40P/abstract).
The detection was confirmed at the peak time 2025-03-30 21:52:21.7 UTC. The T90 duration measured by GRBAlpha is 1.0 s and the overall significance during T90 reaches 6.8 sigma.
The light curve obtained by GRBAlpha is available here: https://grbalpha.konkoly.hu/static/share/GRB250330B_GCN.pdf
All GRBAlpha detections are listed at: https://monoceros.physics.muni.cz/hea/GRBAlpha/
GRBAlpha, launched on 2021 March 22, is a demonstration mission for a future CubeSat constellation (Werner et al. Proc. SPIE 2018). The detector of GRBAlpha consists of a 75 x 75 x 5 mm3 CsI scintillator read out by a SiPM array, covering the energy range from ~50 keV to ~1000 keV. To increase the duty cycle and the downlink rate, the upgrade of the on-board data acquisition software stack is in progress. The ground segment is also supported by the radio amateur community and it takes advantage of the SatNOGS network for increased data downlink volume.